1. Technical Field
The present invention relates to document processing systems and, more particularly, to authenticating documents having both transparent and opaque regions.
2. Description of Related Art
High-speed currency processing machines are used by a variety of financial institutions to count, sort, and verify the authenticity of currency notes. For example, central banks use high-speed currency processing machines to verify deposits received from member banks. Deposits from a vault are delivered to a currency verification processing rooms, where the currency is fed into the high-speed processing machines. The machines count each notexe2x80x94at an average rate of 70,000 notes per hourxe2x80x94and confirm its denomination, fitness, and authenticity, and then automatically bundle fit notes into packages. The fit notes eventually make their way back into circulation when banks order currency from the central bank
Incorrect denominations, suspected counterfeits, and non-machine-readable notes are rejected, and, if necessary, the depositing bank""s account is debited or credited. If necessary, a user may inspect suspected counterfeit notes by hand, paying particular attention to the portrait, scroll work, seals, and colored fibers of each bill, as well as to the weight, color, and texture of the paper. In the United States Federal Reserve System, suspected counterfeits are stamped xe2x80x9cCOUNTERFEITxe2x80x9d and forwarded to the U.S. Secret Service, the Treasury agency charged with maintaining the integrity of the nation""s currency.
To prevent and thwart counterfeiting of currency, a variety of techniques have evolved, such as, for example, the use of serial numbers, special paper, special inks, imbedded threads, and water marks to inhibit counterfeiters ability to copy authentic notes. For example, for each currency produced, a corresponding paper is manufactured. Banknote paper is typically made from cotton pulp which gives it better durability than commercial papers and a very distinctive feel. Much of the time, it is the initial feel of a counterfeit that urges someone to have a closer look at what they are holding. If bank note paper is held under ultra violet light it is dull compared to commercial papers. Furthermore, and more importantly for currency processing machines, the paper manufacturing process allows for a number of features to be created that may be detected by a currency processing machine.
The watermark is one of the most obvious security features of a paper banknote. When held up to the light an image can be seen in the paper, usually a portrait similar to that printed on the note. The image of the watermark is caused by different thicknesses of paper, with light areas of the watermark being a result of thinner paper. The highlighted effect of xe2x80x9cultra thinxe2x80x9d paper is sometimes used as an added security effect in small specific areas within a watermark, e.g. a denomination may appear as a xe2x80x9chighlightedxe2x80x9d portion compared to the main bulk of the watermark. A watermark is an excellent security feature because a counterfeiter is very unlikely to manufacture his own paper.
Currency processing machines have evolved along with the currency to identify the features of a note that identify it as a valid note. For example, optical character recognition (xe2x80x9cOCRxe2x80x9d) technology has been adapted for use in the currency processing field for lifting the serial code or code from processed notes. OCR technology is used, for example, for identifying specific notes processed by a high speed currency processing machine, such as those machines manufactured and marketed by Currency Systems International of Irving, Tex., by lifting a note""s serial code using a camera device and then recording the serial code to the note processed. Other techniques have been developed to identify and verify watermarks.
However, paper currency has a serious flaw in that the average lifespan of paper currency is typically a few years at most. To overcome this deficiency, many countries have recently resorted to having currency printed on plastic notes rather than paper notes. Plastic notes, although more expensive to produce than paper notes, have the benefit of lasting up to ten times as long in circulation as a paper note does. This increased durability results in fewer printings thus providing savings in the number of notes issued that appears to more than offset the increased cost of using plastic notes rather than paper notes.
One other drawback of plastic notes is the inability to use watermarks as a security feature. to overcome this drawback, manufacturers of plastic currency notes have incorporated a transparent window or vignette within the currency note. An example of a currency note of this type is depicted in FIG. 1. Consequently, a need exists for a currency processing machine, system, and method for using this security feature in order to authenticate the currency note.
The present invention provides a document processing machine for identifying and authenticating documents having both transparent and opaque regions and routing the documents appropriately. In many typical embodiments, the documents processed are plastic currency notes having a vignette window containing an opaque pattern on a transparent background. In one embodiment, the document processing machine includes an image capturing device, a light source, a data processing system, and a document control system. The image capturing device captures the image of at least a portion of a document wherein the document comprises transparent and non-transparent regions. The light source emits light toward the image capturing device and is positioned such that the document passes between the light source and the image capturing device. The data processing system is functionally connected to the image capturing device, and obtains the image of the document from the image capturing device, compares the image to a nominal pattern to determine whether the document is authentic, and determines the manner in which the document should be processed based upon whether the document is authentic. The document control system is functionally connected to the data processing system, and receives signals from the data processing system regarding the processing and routing of the document and executes instructions contained in the signals in order to route the document to a proper output bin.